SmogRank / History / Country race
Countries, worst air first, day by day
Each country's typical measured city over the 30 days to every day since January 2023, worst first. Press Play to watch the order change, or drag the slider to any day.
The worst countries for PM2.5 over the 30 days to 28 May 2023: Pakistan 36.9 µg/m³, Chile 34.1 µg/m³ and India 33.9 µg/m³.
- 1Pakistan4 cities36.9
- 2Chile44 cities34.1
- 3India5 cities33.9
- 4Mexico13 cities, was 4122.8
- 5Thailand11 cities, was 3722.2
- 6Serbia3 cities13.8
- 7Greece7 cities12.4
- 8Belgium41 cities12.2
- 9Czechia34 cities11.8
- 10Poland43 cities10.8
- 11Slovakia26 cities10.5
- 12Malta3 cities10.0
- 13Romania6 cities9.6
- 14Hungary8 cities9.5
- 15Austria30 cities9.2
- 16Bulgaria6 cities9.2
- 17Singapore5 cities9.2
- 18Germany194 cities9.1
- 19United Kingdom4 cities, was 438.6
- 20Italy25 cities8.6
+ 10 more countries, 7.8 µg/m³ and below
- 21United States737 cities7.8
Not counted on this day, too few cities measured: Luxembourg since 27 May 2023, The Netherlands since 23 May 2023, Norway since 19 May 2023 and 10 more countries.
Countries counted each day
A country's number is its typical measured city: the median of its cities' means over the 30 days (a city needs 21 of them measured; 5 of 7 on the 7-day race), shown only with 3 such cities. A country whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air; "was" beside a city count marks a month after many cities joined or left. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.